Appaloosa, Belgian Draft, Holsteiner, Quarter Horse ... These are just a few of the over 200 different horse breeds living around the world today.
Although breeds can look wildly different, they all belong to a single species: Equus caballus.
Over thousands of years, people created different breeds by mating horses that have desirable traits. That's why the look of a breed is often related to what it's used for. When these traits get passed down over many generations, a new breed is produced.
For example, about 200 years ago, English horse breeders mated light, swift Arabians with local riding horses. This created the Thoroughbred?a lean, leggy, super-speedy breed used in horse racing.
To find out more about 18 different breeds, go to this site at the American Museum of Natural History: